4

LTC1515 Series

LTC1515-X Shutdown Supply

Current vs Input Voltage

LTC1515-X Step-Down Mode

5V Load Transient Response

INPUT VOLTAGE (V)

0

25

20

15

10

5

0

8

1515 G12

2

4

6

10

85

°C

SHDN = 0V

–40

°C

25

°C

AC COUPLED

100mV/DIV

50mA/DIV

1515 G10

50mA

0mA

AC COUPLED

100mV/DIV

50mA/DIV

LTC1515-X Step-Up Mode

5V Load Transient Response

1515 G11

3.3/5). As with the SHDN pin, the 5/3 pin may be driven with

FB (LTC1515) (Pin 3): Feedback Input. The voltage on this

pin is compared to the internal reference voltage (1.232V)

to keep the output in regulation. An external resistor divider

voltage. Total divider resistance should not exceed 2M.

GND (Pin 4): Ground. Should be tied to a ground plane for

best performance.

Terminal.

SHDN (Pin 1): Shutdown Input. A logic low on the SHDN

pin may still be controlled with 3V logic without causing a

POR (Pin 2): Open-Drain Power-On Reset Output. This pin

will pull low upon initial power-up, during shutdown or

more than 200ms typ.

5/3 (LTC1515-X) (Pin 3): Output Voltage Select. A logic

INPUT VOLTAGE (V)

0

100

80

60

40

20

8

1515 G09

2

4

6

10

LTC1515-X

3V Efficiency vs Input Voltage

LTC1515-X

5V Efficiency vs Input Voltage

INPUT VOLTAGE (V)

2

100

80

60

40

20

10

1515 G08

4

6

8

12

TA = 25

°C

INPUT VOLTAGE (V)

0

100

80

60

40

20

8

1515 G07

2

4

6

10

TA = 25

°C

LTC1515-X

3.3V Efficiency vs Input Voltage